If it is, then you will be fixed up for less than a Big Mac. This may be a lug or screw connection depending on the manufacturer. Just trying to give you as much information as I can for you to be able to help me. Buy new fuse of the same capacity. You are working with live electricity here. To protect the unit against them. Call Air Experts to Fix Your Air Conditioner Issues. Question: How do you determine the size of the fuse if someone stole them and you have no idea what the rating was? Wonderful article! They are probably just a TR type fuse. Thanks again! If you use a fuse that is too small, the fuse is likely to blow more often but if you use one that is too big it could allow more than the rated amount of amperage reach the unit and cause fatal damage to the system. You may have saved my life and my home from fire! Thank you again! Fuses can get hot sometimes so that by itself doesn't mean they are the problem. Answer: The answer is yes, but I cannot in good conscious tell you how because it's a bad idea and fuses are so cheap, so why risk it? If more amps than the air conditioner can handle try to reach the unit, the fuse will blow to protect the condenser. That’s because it is! Answer: Yes. Sounds like you still have one blown fuse. When it comes to air conditioning, it is the capacitor and fuses that are most likely to "feel the heat." Does the notch go up or down? There is nothing between the load side of the disconnect and line side of the contactor, so the measurement has to be the same if measured the same way. Jeanette - There are internal breakers in many air handlers so it's possible those have tripped but those are usually tied to the heat/heat strips, not a/c. Is a safety (device) that tells the HVAC unit, ok - you supposed to draw 30 Amp. on June 08, 2018: After a repair guy got the unit running, worked great for a week. The unit should say right on what the "max fuse size" or "max amperage" is, and you can go buy the fuses. The 25A fuse looked very old and the 20A looked newer. There are no sounds coming out of the unit. The best way to check the fuse is by using a voltmeter. Beyond that I wouldn't feel comfortable trying to talk you into running electrical tests and messing with contactors and such. When you test the voltage, you press the metal end of the lead down on the lugs as directed above. In summer, when you least want to deal with air conditioner problems, your machine is more prone to blown fuses that will require repairs. That should allow some cooling but if it blows as soon as you turn it on, stop there. It just hums. Will it work? Although the air conditioner doesn't have the ability to "know" anything, you're right; your A/C is more likely to break down on the hottest days of the year. Marcy Goodfleisch from Planet Earth on July 28, 2012: This is one task I could probably do myself - I think! G Attore - Since I don't know what you have, I'm going to suggest you look to a local professional or someone you know who can help. Beau, Sounds possible that the capacitor is bad. Oh change the fuses and the fan is not spinning still what could that be. Item #2502424. Beyond that, it's possible the board was fried at the outage. Vote up for useful! Heat is one of the worst things for electrical equipment like an A/C. As for the number of breakers, if you have more than one double pole breaker labeled to your hvac system, then you likely have a heat pump and back up heating system/air handler...in which case only one goes out to the condenser however you could always shut down both to be safe. It should be rather easy to find. Could that be the fan on the inside unit? So if you tried what I've listed here without success, have a look at my article How to Diagnose and Repair Your Air Conditioner (A/C) Capacitor. REMEMBER! Drill through the wall from the outside using the proper size bit for the required opening. Those issues can be fixed easily by a professional. For … Here, we will focus on the fuses and how simple it is to fix this problem. Great post! For those of you who don't have a voltmeter, it's really not a big deal. Before you take your air conditioning unit apart, it is imperative that you … ... the fuse will be in plain sight.or in small control box....be safe Shut all 240 volt breakers down and leave the main on if not sure where your ac breakers are at. Thank you for your articles. Make sure that the circuit breaker is turned off, and open the fuse box to locate the fuse. Is this the same thing? Very good hub on how to replace the fuse in easy steps. Without the stat, there will be no A/C call. Thank you for reading and commenting. Question: We had a severe lightning storm that damages our new A/C unit and furnace. I recently had my blower motor and capacitor replaced, when I had to use the central ac unit. Replaced fuse on the left side and turned on the power at the house panel and checked the voltage at the unit panel and again same issue, the left side no juice. Answer: I recommend you try some of the steps in the article to see if the fuses are the issue. https://stickerdeals.net/fuse-box/central-air-conditioner-fuse-box We have replaced our motor and the control board and still have no air or heat. Still humming. Stay cool! The .5 amp fuse in an LG 48k HVAC minisplit has blown in a snow storm. Ric - Maybe check out this article. Those are usually rated for up to 30 or up to 60 amps, so the fuses should fall within the appropriate range of the disconnect. If you suspect your fuses may be blown, the first thing you'll notice is that the A/C unit outside is not doing anything. As I said at the beginning of this article, your air conditioner's fuses and capacitor are the most likely components to go out on a hot day. It looks just like that you’d find in your car. Charito Maranan-Montecillo from Manila, Philippines on July 12, 2015: Thanks for these tips, Daniel! Answer: It sounds like the lightning may have shorted the unit or panel if it’s blowing a new fuse like that. It turns out that my capacitor was the culprit. But there are no fuses on the outside in the box on the house. I can't thank you enough for putting out easy to understand, helpful information. My AC broke down in the 90+ degree heat yesterday. I found that my AC unit had one 20 amp and one 25 amp fuse. Kathy - And thank you for the feedback. Is this usual I just had my unit installed 3 years ago by a licensed HVAC tech. Your meter should now read voltage in the range of 220 to 240, give or take a few volts. Not sure what kind of system we have. The electric circuit panel has had a 50 amp circuit breaker and the air conditioning unit has not been change in over ten years. I'm sorry I took so long to respond but was on vacation. We tried replacing the fuse that blew, but the new one did the same as soon as we put it in. Thanks for reading. Sorry if that's not what you want to hear. Replace the old fuse with the new one and check whether the AC works. I have another Hub on fuses if you'd like to check. Any ideas??? for pricing and availability. This is not only a great way to cause major damage to your unit but can also be a danger to you and your home. It's almost like the air conditioner knows how much we need it and breaks down on the hottest days of the year.". Question: If the fan on the outside and inside AC unit both come on, then can the fuses be ruled out as the issue? Jillane Barbee - Thank you for the kind words. I did see a comment that they are connected to the furnace..(see I am new at this) it’s running just fine..the fan is not blocked..any suggestions would b helpful if it’s none of the above..before I contact a specialist..thank you. Tested the air handler, looked for leaks, cleaned up and watched videos and studied, but until your article, I had no clue about the fuses. We also just changed the filter also. Loose wire, short or electrical component failure. Question: Where is the 3 amp fuse located in a Tempstar 2-ton unit? Basically you want the amp rating and size to match with a time delay fuse and your all set. The hum has nothing to do with the breaker power so you can hear that thinking you have power when actually you don't. Those will work. I'm not saying that they will blow, just that the odds are better on a hot day. Answer: There is likely a short somewhere in the low voltage (24v) circuit. Before you change the fuse, check the old blown fuse. Some contractors install non-fused disconnects. Which we were told was a sign that it was the fuse on the control board or the control board. In this case, we are taking a simple voltage reading but must still be careful and confident in what we are doing. 2 Ton Heat Pump 14.00 Seer (Rheem/Rudd) and a, 2 Ton Air Handler 14.00 Seer (Rheem/Rudd). Many times, the fuse size and type (typically a "TR" type) are written right on the fuse itself. If the band is broken or melted, replace the fuse. It might be time to hire a skilled HVAC technician or buy a new A/C. If you can't find any amp rating on the fuse or rating plate, you could try and go with a 20 amp fuse (since that is about the lowest rating for any A/C unit) and see if you can get your unit running temporarily while you find out. It is good to know though which is which for future reference. If this fuse gets blown, you will need to have a professional replace it. I switched fuses left and right turned on the power again and now the new fuse has power on the right side and the old fuse on the left has no power but it was working on the left side before. Is the problem most likely a fuse? I just plain couldn't afford a tech and I have been without air for a month. Or will any 20 amp AC cartridge fuse work? I replaced it, thanks to your instructions on another Hub, and it powered right up. Check the volt capacity of the fuse in the disconnect box. You may hear a slight humming, but that's all. It sounds like it may be the issue you're having. There could be several reasons why air conditioner keeps blowing fuse in circuit board. Answer: The max fuse or amp rating (MCA) should be listed on the unit rating plate. I checked the power on the top of the fuse on the left side and it is good but no power at the bottom of the fuse. Passenger Compartment Kathy - I've just commented back on your other post and am glad it worked out. At first I thought your comment was on another Hub. I will have a Electrician come over and do the final hook up, what I wanted to do is mount the disconnect box and run the wire. Answer: The box just means it can handle up to 60 amps and the fuse determines what the protection is. 60 Amp 240-Volt Non-Fuse Metallic AC Disconnect The 60 Amp 240-Volt Non-Fuse Metallic AC The 60 Amp 240-Volt Non-Fuse Metallic AC Disconnect is designed to stop the power going to an air conditioning unit to allow for safe working conditions. Circuits are not labeled clearly enough to read and there is more than one double poled breaker. Air Conditioner Circuit Breaker Keeps Tripping – Reset Your Air Conditioner’s Circuit Breaker (ONCE, … Answer: That would be impossible. Sounds like it COULD be the contactor. Some AC systems also have a fuse at the shut-off box. If you think that's what it is you can replace it for just a couple of dollars to see before getting into larger repairs like a motor or circuit board and if it's not, you're only out a couple bucks. Its a Carrier unit (about 15 years old). To check a fuse, look at the silver-colored band inside the fuse. Question: When repairing my A/C, does it matter which way the fuses are inserted? But all I can find to purchase are FRN-R-35. The fuse is designed to handle a limited amount of amperage based on the maximum amount that the A/C is rated for. Central air conditioner fuse box welcome to my web site this blog post will go over regarding central air conditioner fuse box. NOTE: Not all disconnects have fuses in them. Answer: There are a few high-end systems that may have a 3 AMP fuse in the outside unit but typically, no. I'll be forever grateful. Also saw burn marks on disconnect plug. The A/C still doesn't come on or provide power to the thermostat. Pull out … Where might the problem be? I am thinking it is a fuse inside the Air Handler. What could be the problem? Different Types of A/C Fuses Trying to put copper tubing or aluminum wire in where the fuse goes to try and get the A/C working is a VERY bad idea. Thanks for reading and commenting. The stat tells the furnace to tell the A/C to run. https://dengarden.com/appliances/How-to-Change-an-... With the wiring exposed, you should be able to locate the incoming and outgoing wires. Cheap too. (Yes, people do this, and it never ends well.). What you may not know is that it is a very common issue that can indicate an AC unit in need of repairs. They are the screws that hold the wires down. Return to Central Air Conditioning Unit FAQs . The bare copper wire is the ground wire it needs to be connected to the green wire in the condenser junction box. Here you see fuses rated for different amps as well as the differences in physical size and how fuse reducers (far left and right) can help fit new smaller fuses to old disconnects. Hello Dan, My Ac quit so I checked the fuses. Simply shut down the breaker to the A/C and turn the thermostat to "off.". Is there a right or wrong way to put them in? However, homes that still have fuse boxes will be familiar with the headache of a blown fuse. Kind of cool, eh? I bought new and we put them in with the notch down and the condenser unit hums but the fan doesn't turn. Thank you again for taking the time to help others. Question: Why are 240 volts leaving the A/C disconnect, but 0 volts are being measured at entering contactors? I just purchased a 3 1/2 ton Central Air Condition unit. It could also be the transformer (120/24v). How do I check the fuses in my central air conditioner? It's a pretty easy fix if so. Item #2539009. I replaced the contactor and capacitor and defrost control board. Again, you hope to see voltage in the range of 220 to 240. Ted, this box is designed to be used on anything that has to have a disconnect in the system that a tech can use to service the unit. central air conditioner fuse box, Connect the wires in the air conditioning condenser junction box. Start with the easy fixes. furniturez from Washington on August 08, 2012: I had no idea the replacement fuses were so cheap! Thank you. Its 240 Volt so I checked both leads from the House Panel and the left side was not getting 120 so I figured it was the fuse. Signature 4 Ton 48,000 BTU SEER 14.5 Cooling 95% AFUE 110,000 BTU Heating Complete Split A/C and Gas. There’s usually a switch in your attic, closet, or crawl space … I believe it is the thermostat wire. It's way cheaper than calling the repairman! You may need an HVAC tech and an electrician. That way I can take my time drilling the holes for the box, and line set ensuring it comes out nice and neat. Going to replace all of it. Jim Wood from Surprise Az. Different central air conditioner products affect your comfort and the consistency of indoor temperature. Let's go through this process first and then, for those of you who don't have a voltmeter or are uncomfortable testing voltage; I will give you another method for checking the fuses. Amber - Replacing the fuses is really simple so I wouldn't have much reservation about you doing that. The indoor fan has nothing to do with the indoor fan, but if the outdoor fan is running, then the fuses are not the problem. Answer: They are very cheap. Remember to turn off the thermostat before beginning the fuse replacement process. There are only fuses in the disconnect (if a fused disconnect) at the condenser, but they are much higher rated than 3 amps. There are different kinds but it's often just referred to as the pullout handle, fuse holder, T handle, disconnect...there are a lot of names for it. It's either rated for higher amperage, and we don't want to guess, or there is a short in the wiring, and you may want to contact an electrician or an HVAC technician to locate the problem. Replacing fuses on your central air conditioner simply involves removing the disconnect, popping out the two fuses and replacing them with new ones. ValAdam - Yes it could be and that motor has a capacitor on it that can sometimes be the issue. Would the fan have a fuse also? Hi there I’ve never had a question on a dialogue nor comment so plz bare w me...although these are useful tips I hope you can help give me some input..from what I’ve read n the Hub trying to DIY can b risky so I just want to make sure I get it all b4 I take that risk..my A/C and breaker are brand new..since last summer(1yr)..A/C has been running great then 1 day stopped..no humming noises..nada..no tripped breaker..although these are all new is it still possible for the fuses to burn out so quickly.? Guide to Air Conditioner Specifications and Troubleshooting Electrical Question: The buyers of my home want me to call out an electrician to fix a problem with the air conditioning. Here the "line" is being tested. Try Air Conditioner Coil Cleaning. Barbara - It's always safest to shut down the breaker unless you have a "pull out" disconnect in where the handle itself holds the fuses, then it doesn't matter but if not and the fuses are held in the box, you still have power on one side of those fuses. Maintaining a clean filter not only increased the quality of your indoor air quality, but it also doesn’t force your air conditioner to overwork itself, which could result in blown fuses! Though it is most common that they do, and it's code in many states, some do not. If your air conditioning system is blowing fuses or causing your home’s electrical system to short out, contact the team at Air Experts Heating & Cooling. My husband removed the pullout disconnect when our air conditioner stopped working yesterday and both of the fuses fell out. How to Diagnose and Repair Your Air Conditioner (A/C) Capacitor. Faulty electrical connections. If you replaced the fuse and are having no issues now then that was the problem. Vern, I'm not sure I understand. Should it be replaced with a 25A fuse to match the other 25A fuse in the quick disconnect box? Going to share this. When power came back on; our AC didn't. This is a statement I've heard many times in my 23+ year HVAC career, and it's funny because it's true. It is a fused box that is rated for 30 AMPS or less on a 208, 230 or 240 volt system. Why Is the A/C Humming With the Power Off? We had a clogged drain which my husband unclogged. We flipped the breaker (didn't come on and neither did the thermostat). An AC person probably would charge a hundred dollars or more, without the owner's knowledge that only the fuses may need replacing after a break down. It probably save me hundreds of dollars and I learned something new. When a fuse blows, that's sometimes your A/C's way of communicating that there's a problem. Your units should be under warranty for parts at least so keep that in mind if you need to call a tech. At worst, smaller fuses will blow more easily and overprotect your air conditioner. I can't thank you enough for this article. Question: Are the low AMP fuses (3 AMP) for my heat pump/air conditioner split unit always found in the air handler in the crawl space? The most probable of these are – 1. Thanks for the information! Replace or clean the furnace filter. Power Issues. It is important that you buy the right size fuses for your air conditioning system. I like to know I've been able to help people with these minor repairs that can cost them a lot of money. Kristen Howe from Northeast Ohio on July 12, 2015: Daniel, congrats on HOTD! Changed fuses and tried again, but nothing. Question: How many amps can I use for my A/C with a fuse of 35 amps? I put the wires back, but there is no power at the thermostat & therefore the unit does not work. What else should we check. Loose Electrical Cables – There could be loose electrical cables inside the circuit box or somewhere in your AC which could be causing a short circuit. You should be able to find the size of fuses you need, buy them at your local "big box" retail store, and put them in to test if they were the problem. This article is accurate and true to the best of the author’s knowledge. 'S a very common issue that can indicate an AC unit itself n't... Not have fuses in my central air conditioner oh change the fuse is designed to a... N'T be 100 % from here but that 's a problem this may all sound a. Is n't one on the subject here on HP these tests would narrow! Hvac tech to work with the contactor unless you 're hearing it 's true you. 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